Dietary Neutral Detergent Fiber Research Articles

Effects of source and level of dietary neutral detergent fiber on feed intake, ruminal fermentation, ruminal digestion in situ, and total tract digestion in beef cattle fed pelleted concentrates with or without supplemental roughage.

The effects of source and level of dietary NDF on intake, ruminal digestion in situ, ruminal fermentation, and total tract digestion were evaluated in Hereford steers using a replicated 5 x 5 Latin square design. Diets contained 62 to 64% TDN and included 1) 80% control concentrate (contained pelleted ground grains) and 20% timothy hay (traditional diet), 2) 80% control concentrate and 20% alfalfa cubes, 3) 90% control concentrate and 10% cubes, 4) a completely pelleted diet using corn cobs as the primary NDF source, and 5) 80% textured (rolled instead of ground grains) concentrate and 20% hay. Dry matter intake differed (P less than .05) between the traditional and cube diets due to limited acceptance of alfalfa cubes. Increased (P less than .05) ruminal osmolality, total VFA, and NH3 N and lower (P less than .01) ruminal pH in steers fed corn cob and cube diets relative to steers fed the traditional diet were due to preferential consumption of concentrate over supplemental roughage and the resultant rapid fermentation of concentrates. Potentially degradable DM in the traditional diet exceeded (P less than .06) all other diets, resulting in the increased (P less than .10) extent of DM disappearance despite a slower (P less than .05) rate of DM disappearance. Rate of NDF disappearance and all in situ starch disappearance parameters were similar between the traditional, corn cob, and cube diets. All ruminal digestion parameters involving NDF disappearance were similar between hay diets and between cube diets, whereas rate and extent of starch disappearance differed (P less than .05) between hay diets. Although formulation of diets with different sources of dietary NDF did not affect total tract digestion of nutrients, nutrient availability and ruminal fermentation were altered due to dietary differences in sources of dietary NDF and preferential selection of feedstuffs by steers.

Effects of source of dietary neutral detergent fiber on chewing behavior in beef cattle fed pelleted concentrates with or without supplemental roughage.

Ten 394-kg, ruminally fistulated Hereford steers were used in a replicated 5 x 5 Latin square design to evaluate the effects of source and level of dietary NDF on chewing activities during eating and rumination. Diets contained 62 to 64% TDN and included 1) 80% pelleted concentrate (control; contained ground grains, fibrous byproducts, molasses, and protein, vitamin, and mineral supplements; 36% NDF, 16% CP) and 20% long timothy hay (67% NDF, 8% CP), 2) 80% control concentrate and 20% alfalfa cubes (56% NDF, 15% CP), 3) 90% control concentrate and 10% alfalfa cubes, 4) a completely pelleted diet using corn cobs as the primary NDF source (40% NDF, 17% CP), and 5) 80% textured (coarse instead of ground grains; 42% NDF, 15% CP) concentrate and 20% hay. Diets were formulated to be similar in NDF content, and dietary protein satisfied NRC recommendations. Chewing during eating did not differ (P greater than .10) between diets containing supplemental roughage but decreased (P less than .001) with the corn cob diet. Rumination chewing decreased (P less than .001) with the corn cob and cube diets. The number of chews per day during eating corrected for NDF intake/BW.75 decreased (P less than .05) in the corn cob diet. Rumination periods and duration increased and latency before rumination decreased in hay diets. Steers fed the corn cob diet tended to be more (P less than .10) consistent in time spent eating across 4-h intervals than steers fed the traditional diet. Replacement of long hay with the completely pelleted corn cob diet decreased rumination activity.

Effects of Dietary Neutral Detergent Fiber Concentration and Alfalfa Hay Quality on Chewing, Rumen Function, and Milk Production of Dairy Cows

Six ruminally fistulated Holstein cows (80 d postpartum) were used in a 6 × 6 Latin square to evaluate the effects of dietary NDF concentration and alfalfa hay quality on chewing activities, digestive parameters, and productivity of dairy cattle. Cows received one of six diets formulated to provide three concentrations of dietary NDF (31, 34, and 37%) and two sources of first-cutting, long alfalfa hay. Alfalfa hay was harvested either in early bloom (19.4% CP, 38.8% NDF) or midbloom (16.7% CP, 47.6% NDF) stages of maturity. Dietary NDF concentrations were achieved by adjusting the forage to concentrate ratios. Mean ad libitum DMI was 22.3 kg/d. Increased NDF concentration of the diet corresponded to a linear decrease in milk production (from 26.5 to 24.8 kg/d) and a linear increase in the fat content of milk (from 2.68 to 3.30%). Hay quality had no effect on milk production and composition when diets were formulated for specific NDF concentrations. Total chewing time increased from 767 to 796 and 853 min/d as fiber content of the diet increased from 31 to 34 and 37%, mainly because of increased time spent eating. Rumination time adjusted for fiber intake decreased linearly from 59.0 to 54.2 min/kg NDF as fiber intake increased, and it was higher for the early bloom than for the midbloom hay (57.3 vs. 55.5 min/kg NDF). Effects of decreased forage quality because of the increased maturity of the alfalfa hay can be minimized by formulating diets for specific NDF concentration. For diets formulated with barley-based concentrates, dietary NDF concentrations should be higher than currently recommended with allowance for greater proportions of NDF from concentrates.

Fiber requirements of dairy cows: optimum fiber level in lucerne-based diets for high producing cows

Data from an experiment with high producing dairy cows were used to obtain regression relationships for neutral detergent fiber (NDF) and acid detergent fiber (ADF) as single dependent variables, with dry matter intake (DMI) and digestibility (DMD), rumination and total chewing activities, percent milk fat, 4% fat-corrected milk (FCM) and body weight change. Diets were comprised of alfalfa hay at four stages of maturity, fed with 20, 37, 54 or 71% concentrate. Diet dry matter levels of NDF and ADF ranged from 18.3 to 48.6% and 12.3 to 35.1%, respectively. The relationships of fiber components with body weight and 4% FCM yield suggest that during the period of 10–26 weeks post-partum, levels of fiber less than 29% NDF and 20% ADF were required to sustain a 4% FCM yield of more than 35 kg and maintain a positive body tissue balance. Furthermore, at the same level of dietary NDF, an advance in alfalfa maturity adversely affected ( P<0.05) yield of 4% FCM. Associated with an advance in maturity was a daily change in NDF of 0.86 percentage units and a decrease in FCM of 0.39 kg/day

Effects of pasture and supplement quality on the responses of lactating dairy cows to high energy supplements

An experiment was conducted in which 30 stall-fed dairy cows were fed a basal ration of either good or poor quality pasture (approx. 7 kg DM) and supplemented with varying amounts of either crushed wheat or a pelleted. high energy supplement (0, 4 kg/clay or ad libitum). The cows were in their third month of lactation and were fed their allotted rations for 5 weeks. Where no supplements were fed, the approximate 9% difference in digestibility between pasture types resulted in differences in daily production of 2.4 kg milk/cow, 0.07 kg milk fat/cow and 0.06 kg milk protein/cow, and a difference of 0.4 units of body condition over a 5-week period. Where supplements were fed, responses depended on the interaction between a supplement and basal ration. With good quality pasture as the basal ration, the type of supplement was not important; marginal returns of milk products to extra feeding were similar for both supplements, for example, 1.0 kg milk/cow.day was produced for each additional kg of concentrate consumed. There was a reduction in milk fat production when more than about 5-6 kg DM of supplement was fed. This was due to a depression in the fat content of the milk which was associated with low dietary fibre (&lt;250 g/kg of dietary neutral detergent fibre). However. when pellets were fed to cows offered poor quality pasture. a reduction in milk fat yield did not occur. When wheat supplemented poor quality pasture, on the other hand, deficiencies other than fibre were implicated. While fibre was the most important limitation to productivity when good quality pasture was supplemented with concentrates, protein was the most likely nutrient to limit productivity first when poor quality pasture formed the basal ration. The potential exists for major imbalances of nutrients to occur unless the composition of dietary components is known.

Effects of Dietary Neutral Detergent Fiber Concentration and Supplementary Long Hay on Chewing Activities and Milk Production of Dairy Cows

Effects of dietary NDF concentration on chewing and productivity were assessed using silage-based diets with and without supplemental long hay. Twelve Holstein cows (125 d postpartum) were used in a double 6×6 Latin square to evaluate six diets formulated using high moisture shelled corn and alfalfa silage (37% DM, 23% CP, 48% NDF) to provide three concentrations of NDF: 26, 30, and 34%. At each concentration, an alternative diet was formulated by substituting 15% of the silage DM with an equivalent amount of long alfalfa grass hay (14% CP, 61% NDF). Cows were fed at 85% of ad libitum intake, and ingredients were allocated separately. Increasing NDF decreased milk yield from 20.8 to 19.9 and 19.1 kg/d, for 26, 30, and 34%, respectively. Supplementing diets with hay increased milk production by .7 kg/d, although milk fat content was not affected. Increasing NDF resulted in a quadratic increase in ruminating and total chewing time from 344 and 558 for 26% NDF, to 413 and 651 for 30%, and 414 and 674 min/d for 34%, respectively. Added hay did not increase daily ruminating and chewing time; ruminating time per unit of NDF intake was reduced by hay supplemention (75.3 vs. 69.4 min/kg).

Digestion of diets containing molassed or plain sugar-beet pulp by growing pigs

Large White × Landrace pigs were grown from 25 to 55 kg on diets containing 0, 150, 300 or 450 g kg −1 molassed (M) or plain (P) sugar-beet pulp (SBP) (coded C, 15 M, 30 M, 45 M, 15 P, 30 P, 45 P, respectively). The apparent digestibilities of dry matter (DM), nitrogen (N), non-starch polysaccharides (NSP) and neutral detergent fibre (NDF) of the diets were determined when pigs attained live weights of 27 and 50 kg. Diets contained similar amounts of DM, N and gross energy (GE). Levels of dietary NSP and NDF increased with SBP content. The major NSP residues in SBP were uronic acids, arabinose and glucose, in the approximate ratio of 1:1:1, whereas glucose accounted for 66% of the NDF NSP. In 27-kg pigs given Diet 45 P, digestibilities of DM and N were significantly reduced relative to the control. In contrast, digestibilities of the NDF and NSP fractions of most SBP diets were higher than those of Diet C. When pigs had attained 50 kg live weight, digestibilities of all components had increased, and there were no significant differences in the digestibility of DM between each of the seven diets. However, the abilities of 50-kg pigs to digest the N and NSP fractions of Diet C were higher and lower respectively, than those of similar pigs fed Diet 45 P. The arabinose and uronic-acid content of the diets were highly digestible as were the minor components mannose, galactose and non-cellulosic glucose. Xylose and glucose were poorly digested by 27-kg pigs, but their digestion by 50-kg pigs was substantially improved. Increasing inclusion levels of SBP resulted in concomitant increases in faecal bulk. These results indicate that young pigs fed diets containing up to 300 g kg −1 MSBP, can digest DM and N as well as, and NDF and NSP better than, pigs fed a conventional diet without SBP.

Effect of ammoniation and energy supplementation on the utilization of wheat straw by sheep

Two experiments were conducted with mature wethers to study the effects of ammoniation of wheat straw and type (Experiment 1) and level (Experiment 2) of energy supplementation on straw intake, digestion and utilization of nutrients. In Experiment 1, sheep were fed coarsely chopped untreated (US) or ammoniated wheat straw (AS). The AS diets were supplemented with whole shelled corn (WSC), cottonseed hulls (CSH) or both. A fourth diet of US was supplemented with WSC, CSH and urea (5 g per head per day). Whole shelled corn and CSH were fed daily in amounts of 10 and 5 g per 0.75 kg, respectively. In Experiment 2, treatments consisted of coarsely chopped US and AS and 3 levels of supplemental WSC (i.e., 0, 10 or 20 g per 0.75 kg) fed daily. Sheep fed US were also supplemented daily with 15 g urea per head. Straw intake of sheep supplemented with WSC and CSH was increased 30% (not significant, P > 0.05) by ammoniation in Experiment 1, and was increased 33% ( P < 0.01) by ammoniation in Experiment 2. Straw intake was not decreased by supplementation with WSC (10 g per 0.75 kg) in Experiment 1, but decreased quadratically ( P < 0.05) as the level of WSC supplementation increased from 0 to 20 g per kg 0.75 in Experiment 2. Apparent digestibility of total diet neutral detergent fiber remained unchanged with WSC supplementation in Experiment 1, but decreased linearly ( P < 0.01) as the level of WSC supplementation increased in Experiment 2. In Experiment 2, ammoniation of straw decreased ruminal NH 3-N concentrations after feeding ( P < 0.10). Nitrogen balance was also increased ( P < 0.01) by supplementation of AS with WSC (Experiment 1) and in a linear fashion ( P < 0.01) as the level of WSC supplementation increased in Experiment 2. Ruminal NH 3-N concentrations decreased linearly ( P < 0.01) with level of WSC supplementation in Experiment 2. Ammoniation increased ( P < 0.01) loss of fecal N and the amount of nucleic acid (RNA) excreted in feces in Experiment 2. Regression of N retention (g day −1; Y) on digestible OM intake (DOMI, g per 0.75 kg; X) observed in Experiment 2 resulted in the following relationships: (US) Y = 0.74 + 0.079 X; ( R 2 = 0.06, n = 24); (AS) Y = −5.67 + 0.240 X ( R 2 = 0.46, n = 24). For every g per 0.75 kg increase in DOMI, the increase in N retention was 3-fold greater ( P < 0.10) with AS versus US diets. These results emphasize the need to supplement ammoniated straw diets with a suitable source of energy to enhance utilization of the added nitrogen.

Steers grazing blue grama rangeland throughout the growing season. II. Site and extent of digestion and microbial protein synthesis.

Effects of advancing forage maturity and drought-induced summer dormancy on site and extent of digestion and microbial protein synthesis in beef steers grazing native blue grama rangeland were evaluated in four sampling periods. Five steers (avg initial wt 227 kg) fitted with ruminal, duodenal and ileal cannulae and three steers cannulated at the esophagus freely grazed a 12-ha study pasture. Sampling periods lasted 11 d and started June 2, which was during the early growing season (EGS); June 22, during early summer dormancy (ESD); July 21, during late summer dormancy (LSD); and August 25, 1985, during the late growing season (LGS). Dietary N content was lower (P less than .05) in ESD and LSD than in EGS and LGS. Neutral detergent fiber (NDF) content was lower (P less than .05) in EGS than in other sampling periods. Ruminal organic matter (OM) digestion was lower (P less than .05) in ESD than in EGS, probably because of increased dietary NDF and lower N content. Ruminal OM digestion was greater (P less than .05) in LSD and LGS than in ESD because of increased fiber digestion. Neutral detergent fiber and acid detergent fiber (ADF) digestion occurring in the rumen was greater (P less than .05) in LSD and LGS than in EGS and ESD. Organic matter digestion in the small intestine and OM, NDF and ADF digestion in the hindgut were similar for all sampling periods. Over 90% of the fiber digestion occurred ruminally.(ABSTRACT TRUNCATED AT 250 WORDS)

Responses to dietary additions of fiber (alfalfa meal) in growing pigs housed in a cold, warm or hot thermal environment.

Five trials involving 112 individually-penned animals were conducted to determine the effects of dietary fiber additions (0 or 10% dehydrated alfalfa meal) on the rate and efficiency of growth and carcass characteristics of growing pigs housed in a cold (10 C), thermoneutral (22.5 C) or hot (35 C) thermal environment. Cold exposure (10 C) depressed efficiency of feed and energy utilization, carcass length, backfat, cold carcass dressing percentage and percentage lean cuts. Exposure to the hot environment resulted in depressed live weight gains but did not alter the efficiency of feed utilization. Dietary additions of alfalfa meal depressed daily gains by 1, 3 and 5% in pigs housed in the cold, warm and hot environments, respectively, and gain:feed ratios by 1, 7 and 10%. Ingestion of the fibrous alfalfa meal depressed cold carcass dressing percentage in the 10 and 22 C environments as compared with the basal diet. Based on these data, the nutritional value of fibrous feedstuffs (15% total dietary neutral detergent fiber or less) for growing pigs allowed to consume feed ad libitum is greater in animals housed in a moderately cold vs a warm or hot thermal environment.

Breath hydrogen and methane: poor indicators of apparent digestion of soy fiber

To examine whether end-alveolar breath hydrogen and methane could be used as indicators of fiber digestion in humans, 16 male subjects were fed four fiber-free, complete liquid diets with 0, 30 g (heat processed), 30 g, and 60 g/day soy polysaccharide. Breath hydrogen was measured hourly and breath methane every 4 h on days 6 and 8 of each study period. Feces were collected, homogenized, dried, and analyzed for neutral detergent fiber (NDF). NDF in diets was determined and apparent NDF digestibility calculated. NDF from soy was extensively fermented, <80%, on the fiber-containing diets. No significant relationship was found between breath-gas excretion and fiber digestion, although breath-gas values varied greatly. Breath hydrogen and methane were not significantly different when subjects consumed diets containing 0, 30, or 60 g soy polysaccharide.

Effects of Particle Size and Breadmaking on Physiological Responses of Meal-Fed Rats to AACC Wheat Bran

Adult rats were meal-fed diets containing 20% AACC certified hard red spring wheat bran (as received, ground, incorporated into bread) for 12 days to determine the short-term processing-induced effects on gastrointestinal function and serum lipids. Fecal nitrogen, fecal fat, transit time and serum triglyceride levels were influenced by the consumption of wheat bran, but not by the grinding or breadmaking procedures. Reduction of bran particle size decreased dietary hemicellulose and reduced fecal bulk as well as defecation frequency. Incorporating bran into bread reduced dietary neutral detergent fiber (NDF), reduced intestinal passage rate of the ground wheat bran and decreased degradation of dietary fiber components in the unground wheat bran.

The digestion of fibre by pigs. 2. Volatile fatty acid concentrations in large intestine digesta.

The effect of including lupin (Lupinus sp.) hulls, maize cobs, wheat bran and lucerne (Medicago sativa) stems in a basal fibre-free diet on the concentrations and the relative proportions of volatile fatty acids (VFA) in the proximal colon of pigs, 17-18 h after feeding, was studied. Concentrations of total VFA in the proximal colon increased with increasing levels of neutral-detergent fibre (NDF) intake, and this increase was highly dependent on the source of NDF in the diet. Molar proportions of the VFA were significantly affected by the level of NDF intake only in the cases of acetic and butyric acids, whereas the source of dietary NDF had a marked influence on the molar proportions of all acids. The results indicate that the extent of fermentative breakdown of fibre in the pig intestine can be influenced substantially by the type and the level of fibre in the diet.

The digestion of fibre by pigs. 3. Effects of the amount and type of fibre on physical characteristics of segments of the gastrointestinal tract.

The aim of the study was to determine the relative effects of feeding growing pigs with graded amounts of neutral-detergent fibre (NDF) from various sources on the empty wet weight of segments of the pig gastrointestinal tract, on the weight and moisture content of their digesta, and on the pattern of digesta movement in them. Increased NDF intakes were associated with significantly higher wet weights of all gastrointestinal segments and increased lengths of the caecum. The lengths of both the small and the large intestines were unaffected by the ingestion by the pigs of different amounts of NDF from various sources. However, the caecum responded to these increased intakes of NDF by significant increases in length. The source of NDF in the diet was a factor that markedly influenced both the length and the weight of the distal colon. The nature of these increases in weight and length morphologically and their biological significance have not been determined. Despite some significant differences, neither the type nor the level of dietary NDF had any appreciable effect on the dry weight and on the proportion of dry matter (DM) of the contents in the contents in the stomach. As the level of NDF intake was increased, more undigested dietary material was found in all segments of the digestive tract of the pigs. The proportion of DM in the residues decreased progressively from the caecal contents to the contents of the distal colon. In most cases the degree to which the level of NDF intake affected the weight of the contents and the proportion of DM in them was highly dependent on the source of NDF in the diet. The distribution of the feed consumed in the morning and in the evening, as measured with stained feed particles and polyethylene beads, was extremely variable. It is concluded that prolonged intakes by pigs of diets containing high levels of fibre may lead to a hypertrophy and hence increased weight of segments of the gastrointestinal tract.

Binding of bile salts to dietary residues

The binding of glycocholic and glycochenodeoxycholic acids to dried defatted residues of homogenized diets consumed by four dietary groups has been measured. The four groups were true vegetarian Seventh-day Adventists (SDA), lacto-ovo vegetarian SDA, nonvegetarian SDA, and the general population. Glycocholic acid was bound to the same extent (7 to 9%) by all four dietary residues. The true vegetarian SDA residues bound significantly more glycochenodeoxycholic acid than those of either lacto-ovo vegetarian SDA (p < 0.001) or nonvegetarian SDA (p < 0.001). The general population residue bound significantly more glycochenodeoxycholic acid than did those of nonvegetarian SDA (p < 0.001). Binding of glycochenodeoxycholic acid was significantly correlated with dietary neutral detergent fiber (p < 0.001), hemicellulose (p < 0.01) and cellulose (p = 0.01). There was no correlation between the binding of glycochenodeoxycholic acid and dietary lignin, pectin or cutin.

A Study of the Relationship Between Performance and Dietary Component Digestibilities by Swine Fed Different Levels of Dietary Fiber

A 49-d feeding trial, using 192 growing-finishing pigs (avg initial wt, 32 kg), was conducted to identify pigs of widely differing average daily gains (ADG) when fed 16% crude protein diets containing either 0, 7.5 or 15% corn cobs. There were linear decreases in both ADG (P less than .01) and gain/feed (P less than .001) with increasing levels of dietary corn cobs. Average daily feed intake increased linearly (P less than .001), but average daily digestible energy (DE) intake tended to decrease (P less than .08) with increasing dietary fiber level. Gain/DE was not apparently affected by dietary treatment. At the end of the feeding trial, 27 pigs, nine from each dietary treatment, were selected on the basis of ADG to represent pigs of above average, average and below average performance during the feeding trial. Previous ADG of the pigs selected for these were .93, .81 and .69 kg, respectively. In these pigs, plasma levels of glucose decreased (P less than .01) linearly, but urea N tended to increase (P less than .08) linearly with increasing level of dietary corn cobs. A digestion trial was conducted to determine if previous performance of the selected pigs could be related to the digestibilities of dietary components and the retention of N by these pigs. Nitrogen and dry matter (DM) digestibilities and dietary DE decreased linearly with increasing level of dietary corn cobs. The digestibilities of dietary neutral detergent fiber (NDF) and acid detergent fiber (ADF) decreased both linearly and quadratically with increasing level of corn cobs. Regardless of dietary treatment, no significant differences in any of these criteria were observed among pigs selected on the basis of widely differing ADG during the feeding trial.

Voluntary Intake and Digestibility of Legume and Grass Diets Fed to Lactating Cows and Growing Wethers

Two complete mixed diets (77% forage, 23% concentrate) were fed to 20 Holstein cows during the second third of lactation and to 7 wether sheep to compare voluntary intake and digestibility of the two diets and to compare the utilization of the diets in the two animal species. Diet neutral detergent fiber percent, and as-fed bulk density (kg/liter) for the alfalfa hay diet (alfalfa diet) were 42.3 and .20. Respective values for the orchardgrass diet (grass diet) were 47.5 and .12. Dry matter intake of cows fed the alfalfa diet (164 g/kg body weight·75) was greater whereas volume intake (837 ml/kg body weight·75) was less than the respective values (136 g/kg body weight·75 and 1097 ml/kg body weight·75) for the grass diet. Daily intakes of digestible energy and neutral detergent fiber and production of 4.0% fat-corrected milk for the alfalfa and grass diets were not different. Comparable intakes of dry matter and volume by sheep for the alfalfa diet were 63 and 323 and for the grass diet were 64 and 519. Diet digestibility was lower in cows than in sheep. Estimates of diet digestible energy from National Research Council tables overestimated actual digestible energy of the high forage diets fed ad libitum to lactating cows.